A242392 Irregular table which shows in row n the list of distinct integer arithmetic means of distinct divisors of n, or zero if n <= 2.

0, 0, 2, 3, 3, 2, 3, 4, 4, 3, 5, 6, 2, 5, 6, 3, 6, 6, 2, 3, 4, 5, 6, 7, 8, 7, 4, 8, 2, 3, 4, 5, 5, 6, 7, 8, 7, 4, 8, 2, 3, 4, 6, 8, 9, 10, 3, 5, 6, 7, 8, 9, 9, 2, 4, 5, 6, 7, 8, 9, 10, 12, 10, 3, 5, 6, 7, 9, 10, 11, 12, 15, 2, 4, 5, 8, 12, 14, 6, 9, 12, 12

Offset

1,3

Links

Table of n, a(n) for n=1..82.

Example

Table starts:
0,
0,
2,
3,
3,
2, 3, 4,
4,
3, 5, 6,
2, 5, 6,
3, 6,
6,
2, 3, 4, 5, 6, 7, 8,
7,
4, 8,
2, 3, 4, 6, 8, 9, 10,
3, 5, 6, 7, 8, 9,
9,
2, 4, 5, 6, 7, 8, 9, 10, 12,
10,
3, 5, 6, 7, 9, 10, 11, 12, 15,
2, 4, 5, 8, 12, 14,
6, 9, 12,
12.
2, 3, 4, are in 6th row because:
1) (n/6 + n/2)/2 = (6/6 + 6/2)/2 = (1 + 3)/2 = 2,
2) (n/6 + n/3 + n/2 + n/1)/4 = (6/6 + 6/3 + 6/2 + 6/1)/4 = (1 + 2 + 3 + 6)/4 = 3,
3) (n/3 + n/1)/2 = (6/3 + 6/1)/2 = (2 + 6)/2 = 4.

Crossrefs

Cf. A027750.

Sequence in context: A191246 A248222 A107918 * A002963 A046677 A283104

Adjacent sequences: A242389 A242390 A242391 * A242393 A242394 A242395

Keyword

nonn,tabf

Author

Ilya Lopatin and Juri-Stepan Gerasimov, May 12 2014

Status

approved